活动褶皱地区横向河演化与风口形成的研究进展和案例分析  

DEVELOPMENT OF TRANSVERSE DRANAGES AND FORMATION OF WIND GAPS ON ACTIVELY GROWING FOLD:REVIEW AND CASE STUDY

作　　者：曹喜林[1,2] 耿豪鹏 潘保田[1] 胡小飞[1] CAO Xi-lin;GENG Hao-peng;PAN Bao-tian;HU Xiao-fei(Key Laboratory of Western China’s Environmental Systems Ministry of Education,College of Earth and Environmental Science,Lanzhou University,Lanzhou 730000,China;College of Geography Science,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]兰州大学资源环境学院,西部环境教育部重点实验室,兰州730000 [2]南京师范大学地理科学学院,南京210023

出　　处：《地震地质》2020年第3期670-687,共18页Seismology and Geology

基　　金：国家自然科学基金(41730637,41571003,41501002)资助。

摘　　要：河流偏转和风口发育是横向河流域最显著的地貌现象,其形成体现着区域抬升和河流侵蚀间的平衡,并受控于断层侧向生长、连接与几何形态等构造过程以及影响河流侵蚀的气候和岩性要素。风口与横向河网的演化可用于评估相关断层活动的速率和方式,探索河流侵蚀与构造抬升之间的相互作用以及复杂环境下沉积系统的形态,研究成果对地貌学、地震灾害、油气储藏等学科领域具有重要的理论意义。文中围绕影响风口形成与保存的地质地貌过程,对过去20a活动褶皱区域的横向河演化研究案例进行了初步总结。最后以河西走廊地区的合黎山—金塔南山为例,探讨在褶皱隆起和水动力变化的条件下黑河在该区域的演化过程。分析认为现代黑河约1.1Ma BP穿过合黎山,而随着合黎山的生长、黑河水动力条件的变化,黑河偏转到达金塔南山区域;由于合适的水沙比与抬升速率,金塔南山区域早期抬升时处于夷平状态;约0.23Ma BP以来,大部分支流无法到达金塔南山区域,黑河在金塔南山与合黎山连接的区域下切,形成正义峡。The most compelling phenomena for transverse drainage in active fold belt are lateral diversion of channels and development of water/wind gaps.This phenomenon is the result of competition between uplift and erosion,which is controlled by fault vertical/lateral propagation and segment linkage,fault geometry,climate condition and lithology.Previous studies found that the higher the uplift rate is,the greater number of wind gaps form,and the variation of the uplift rate is also critical to the sustainability of transverse rivers.Lateral propagation and linkage of several separate folds in fold-andthrust belts will lead to defeat of streams and diversion into a trunk drainage;if the trunk is still unable to keep pace with uplift,water gap will be abandoned and left as a wind gap.For lateral propagation of an anticline associated with development of tear faults,the locations of wind/water gaps are likely to coincide with the trace of tear fault and it’s not quite clear about the relation between tear faulting and stream deflection.Nonzero dip of the underlying detachment induces a lateral surface slope in the direction of fault propagation,which in turn makes rivers deflection more efficient.Climate and rock erodibility control the water/sediment discharge,and further influence river transport/incision capacity.The changing climate and rock erodibility conditions enable river to abandon the current waterway to create a wind gap unless they could down-cut through a growing fold.However,the role of climate cycle in the formation of wind gap is still controversial.In addition,wind gaps are commonly developed along the divides where parts of longitudinal river have been captured by transverse catchments.Generally,the development of transverse drainages and the formation of wind gaps in nature are result from a combination of tectonic and fluvial process.The wind gap pattern and transverse drainage evolution in fold-and-thrust belts contain plenty of information on fault growth,interaction between tectonic uplift and flu

关 键 词：活动褶皱 横向河 风口 黑河 合黎山 金塔南山 

分 类 号：P542[天文地球—构造地质学]